This distinction is entirely useless. Who cares if something is produced for the iPad or not? The iPad is a distribution channel for producers. People can only consume what's been produced, right? Producing content for the iPad is producing content nonetheless.
we're not only in an age of consumer-orientated devices, which is great, but also in an age of such wealth and technological progress, that we have specialized machines serving different, specialized purposes.
in which way could the ipad be a tinkerer device more than it is now? well, it could have an accessible *nix core with the ability run a package manager like apt and in general the ability to modify the core experience of the device. although it'd be great to have that, there wouldn't be that much use to it. everything in and on this device is highly optimized for the one experience every buyer comes to appreciate. any core modifications would probably deteriorate this experience rather than improve on it. but whatever i'm saying here doesn't actually matter, since every enthusiast has been able to do exactly that, get root access to any iOS device, since the first iphone. of course, in order to properly modify the devices behaviour, a lot of back-engineering is needed. but hey, that's what tinkering is all about, isn't it?
i'm digressing... my actual point here is: specialized devices for specialized purposes. a fully capable linux machine with the most open os available today and the benefit of a prospering eco-system costs you a mere 35 bucks or even less. this is any tinkerer's dream and it's real and accessable to anyone. what again are we whining about here?
the ipad/iphone are produced within a highly competitive market. that they're locked up is, objectively, a matter of protection of investments. also, because they can.
to sum it up, the ipad isn't a tinkerer device because
1) it doesn't even have a keyboard. how would you tinker with it?
2) actually you can root the device and modify the underlying core processes
3) going beyond this would need official documentation by apple of it's secret apis etc., which isn't economically feasable in this highly competitive market. i mean samsung copies whatever the fuck is coming out of cupertino, atm at least.
4) it doesn't need to be more than a consumption device, because for the tinkerers there exists the most vivid environment imaginable: cheap hardware, a free, open, up-to-date os and a brimming eco-system of developers and software.
It is a truly abysmal creation device, though. Typing on it is slower than on a physical keyboard. You can't switch between apps very easily, so doing anything where you'd have to reference or copy information is greatly hindered. If you want to use "non-visible" keystrokes (like control or win/cmd), it's a non-starter. The OS is heavily locked down and so divorced from the concept of "processes" and "files" that it is designed to not simply hide the internals, but to actively deny that they exist. While it's possible to create with it, it's absolutely the wrong tool for it. The hacker ethos is adamant about using the right tools for the job. Using the iPad as a creation platform (with, perhaps, the sole exception of a finger-painting device) is akin to using a pair of scissors like a bandsaw. You can get it done, maybe, after a lot of work and a lot of pain, but it's the wrong tool for the job.
I really appreciate how usable the iPad is as a device for people who simply want to consume content. But, I think that to treat it as the "next generation of computing" (see also: the "post-PC era") does a tremendous disservice to our industry, our children, and our society as a whole. Breeding out curiosity and penalizing the tinkerer is not a good thing. I am a programmer because my computer is my artist's canvas - code is the medium with which I paint. It is a deeply creative, deeply engaging, deeply expressive device for me. The iPad is not - and by design, cannot be.
It's a fantastic device for consuming content, but if you're going to sign up with the iPad, you're going to have to sign up to the consumer-oriented culture it is infused with. That'll be $0.99. Please don't peek behind the curtain.
Edit: Because I'm sure it'll be brought up, don't confuse creating content for the iPad (with your full-fledged Mac computer) with creating content on the iPad. The former is, of course, happening all the time, and that's great. But unless you're buying the device plus the $99 developer's license to be able to program it, you're not buying a "production" device.